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Sleeping with lights on is bad for you: Here’s why

How often do you sleep with your lights on? This might seem almost irrelevant, but sleeping with the lights on can negatively impact your health. Whether the light source is the television, laptop, streetlights, or other lighting fixtures, it has mental and physical effects on your health.

It’s estimated that more than half of adults sleep with some kind of light on. If you’re one of them, it’s advisable to put an end to this unhealthy habit. Here is why light exposure while sleeping is bad for you.

Woman sleeping in bed with light on
It disrupts your sleep cycles

When exposed to light during bedtime, your body’s circadian rhythm is disrupted. This causes the brain to produce less melatonin hormones, which help you fall asleep.

Naturally, as nighttime approaches, your body starts producing higher levels of melatonin. So, light exposure before or during sleep prevents you from getting sleepy because it slows the sleep-inducing hormone production. Light exposure also can cause you to not get enough REM (rapid eye movement) sleep, which is the most restful.

It causes depression

Lights exposure during bedtime has also been linked to depression. This is particularly true if you use electronic devices, which are known to produce blue light. It leads to depressive symptoms such as mood swings and irritability.

Children who don’t get enough sleep due to sleeping with the lights on tend to be hyperactive. So, it’s wise to switch off as many lights as possible.

It leads to insomnia

Disruption of sleep cycles due to light exposure while sleeping is just the beginning. Over time, this develops into insomnia. You’ll find yourself waking up several times during the night. Sometimes, insomnia makes it difficult for you to fall asleep.

Even if you manage to get to sleep, you’re likely to wake up feeling very tired. Your insomnia can be acute or chronic depending on your sleeping habits and other factors, such as medications and inactivity.

Improving your sleeping habits and reducing light exposure during bedtime can help manage acute insomnia. For chronic cases, you’ll need to get behavior therapy or medical diagnosis for any underlying condition.

It induces migraines

You’re also likely to experience migraines, especially when you watch TV in bed or use gadgets before sleeping. The blue light from these electronics usually causes migraines.

The light leads to oxidative stress, which means your body fails to get rid of toxins effectively. The retention of toxins within the central nervous system is usually the major cause of migraines. Apart from the migraines, it also leads to eye strain and even eye blindness in severe cases.
Your migraines tend to worsen when you experience other sleep problems, such as insomnia.

It causes hormonal imbalance

As noted before, sleeping with the lights on causes the brain to produce less melatonin hormone. This hormone is responsible for your normal sleep-wake cycle. When this hormone is imbalanced, it affects other aspects of your body, such as reproduction, blood pressure, and inflammation.
Sleep deprivation due to light exposure also affects the production of several other hormones, such as antidiuretic hormone (ADH), growth hormone, oxytocin, and prolactin. Some of these hormones are usually produced when you sleep, so failing to get enough sleep means insufficient production.

Eventually, you experience hormone imbalance, which causes a wide range of symptoms, such as fatigue, weight gain, puffy face, constipation, heat or cold sensitivity, unexplained weight loss, dry skin, and increased or decreased heart rate.

It’s linked to obesity

Some studies have shown that obesity was prevalent in people who had a habit of sleeping with the TV on. Since the lights affect your sleep time, you have a 15 percent higher risk of becoming obese. People who sleep less than five hours have an even higher risk.

Apart from this, there are also several ways that poor sleep quality increase your risk of becoming obese. One is that being sleep deprived means you’ll always be too tired, and this means you’re likely to avoid exercising, which helps to burn calories.

Also, not sleeping well during the night means you’re likely to wake up often, which presents more opportunities to eat. As such, the more you eat, the more calories you get. Lack of sleep also causes an imbalance of hormones that controls appetite, meaning you’ll always be hungrier than those who get enough sleep.

Final thoughts

Man sleeping with lights on
David Prado Perucha/

Sleeping in the dark gives you quality sleep, and it’s something you should strive to do every day. Adults should get about seven to nine hours of sleep daily. One way of improving your sleep quality is through switching off lights and avoiding gadgets before bedtime.

The light generated by fixtures and gadgets keeps you awake longer, which affects your regular sleep-wake cycle. Even before sleep, you should limit your computer use and television viewing. If possible, avoid having a TV in your bedroom. Over time, you’ll notice your sleep quality has improved.

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